Halogen exchange of flouroalkyl amines synthesis of polychloro- and bromo-trialkylamines

Fluoralkylamines (CF₃)_3?nN(CHF₂)_n, n = 1 to 3, and analogous C₂F₅ derivatives exhibit a selective reactivity of the CHF₂ group towards Lewis acids like BCl₃, TiCl₄ and BBr₃, CHCl₂ and CHBr₂ groups being formed in nearly quantitative yield. Halogenated trialkylamines of the general formulae (CF₃)_3?nN(CHCl₂)_n, n = 1 to 3, and (CF₃)_3?nN(CHBr₂)_n, n = 1 and 2, were obtained for the first time and characterized by nmr, ir, Raman and mass spectra. The halogen exchange reaction proceeds via an intermediate immonium cation, but the chloro and bromoalkyl amines are non-ionic. Both (CF₃)₂NCHF₂ and (CF₃)₂NCHCl₂ undergo photochlorination to yield (CF₃)₂NCF₂Cl and (CF₃)₂NCCl₃.